1. Field of the Invention
The present invention relates to a tray for integrated circuits, particularly those of the ball grid array (BGA) type. The tray is stackable and includes an upper side and a lower side, wherein the upper and lower sides of successive trays form storage pocket areas therebetween. More particularly, one of the sides includes corner elements which define the periphery of the storage pockets and which restrain the integrated circuits in directions (X-Y) parallel to the floor of the tray. This side further includes lateral elements which extend into the storage pockets thereby forming a ledge to restrain the integrated circuits in the direction (Z) perpendicular to the floor of the tray. Another of the sides includes lateral elements which define the periphery of the storage pockets and which restrain the integrated circuits in directions (X-Y) parallel to the floor of the tray and further corner elements which extend into the storage pockets thereby forming an inverted ledge to restrain the integrated circuits in the direction (Z) perpendicular to the floor of the tray. These corner elements and lateral elements rise or erupt from the floor of the tray.
2. Description of the Prior Art
In the prior art, it is known to use stackable trays for the storage and transportation of integrated circuits, particularly ball grid array (BGA) integrated circuits. These stackable trays typically form discrete storage pockets for engaging individual chips. Moreover, these trays are sometimes used as a carrier to engage and position the chips for automated assembly apparatus. In this type of application, the use of lids separate from the trays makes the automated assembly process more difficult by adding steps to remove the separate lids.
Moreover, it is imperative that these stackable trays provide substantial mechanical and electrostatic/electromagnetic protection for the chips.
Some examples of the prior art stackable trays can be found in U.S. Pat. No. 5,400,904 entitled “Tray for Ball Terminal Integrated Circuits”, issued to Maston et al. on Mar. 28, 1995; U.S. Pat. No. 5,103,976 entitled “Tray for Integrated Circuits with Supporting Ribs”, issued to Murphy on Apr. 14, 1992; U.S. Pat. No. 5,080,228 entitled “Integral Carrier and System for Electrical Components”, issued to Maston et al. on Jan. 14, 1992; U.S. Pat. No. 5,000,697 entitled “Carrier System for PGA Electrical Components”, issued to Murphy on Mar. 19, 1991; U.S. Pat. No. 4,765,471 entitled “Electrical Component Carrier”, issued to Murphy on Aug. 23, 1988.